for those who have installed a 4.0 UDP......
 

was it difficult? what in YOUR opinion was the hardest part?

Hardest part is holding the damned crank from turning while you loosen the pulley bolt. If you leave the radiator in, a tool should be made to hold it so the crank won't turn. If you take the radiator out, then an impact would get it done quickly.

so an impact will work without holding the pulley :shrug: ?

i have a body lift and my radiator is mounted in the stock location because of the efan, so i have plenty of room to get an impact in there with the radiator in the truck.....

you can also go to like autozone and rent the tool to hold the crankshaft, i used to do it when i worked at percision tune. its like 20 bucks to rent it but its definately worth having the right tools....

Just put a glove on or use a rag just in case and hold it with your hand or leave the belt on. With the impact, that is all it should take.

sweet.....did you install the other pulley's also?

i think everone agrees that loosening the stock bolt is the tuff part. an impact fit in mine without removing the radiator, but the fan needs to removed.

witha manual tranny you can put it in gear to kepp it from turning. other than that- the right tools make it failry easy. fan removal tool- pulley puller. all should be free loaners from auto zone.

wouldn't the auto tranny hold it also?

what is the lead time on these pulley's Wayne?

in stock so 3-4 shipping days UPS.

i think the tq converter allows slipping. it may hold enough. I'm not sure.

would it be worth my while to get the other pulleys also? and are they hard to install?

Just the crank.

The other pulleys would be easy, but the gains they may offer might not make them worth it on the 4.0. They sure make a difference on a V-8, but I haven't seen any tests on a crank, alt., and water pump combo for the 4.0.

the thing is, i play my stereo a lot at idle.....that is my main concern.....and i dont want it to overheat.....since i do a lot of slow arse driving at the shows i go to....

my best guess is the extra underdrive for the water pump will replace the HP lost from the overdrive alt pulley, with oem charging being the net gain.

the hp (gain or lost) of any pulleys past the crank pully will be negligible. Color is a legitimate factor for some (me included). If underhood appearance is a factor then it makes the value of the other two pulleys that much greater.

maurice- overheating has not been an issue. Enough guys have put them on in warm states. guys with water temp gauges are reporting back normal water temps. I've ran it with and without an e-fan.

so if i put an underdrive pulley and an alternator pulley i would be set?......that would save me $85 for something else :006:

Jusnes was the first I heard with this idea- if you have the X Cal II just bump your idle up to 850 rpm. this gets you past the weak spot on the voltage at idle issue.

My idle is higher than stock mainly for the smoothness, but it will help with the charging issue (if any).

duh...........might bump it up to almost a 1000 rpm.......150 rpm aint gonna waste that much extra fuel....

voltage issues with UD Pulleys- it needs to be realized that IF there is an issue it will be at IDLE only. 200 rpm higher and it is gone.

I ran with a set up that most people woiuld think would leave me stranded. underdrive crank, underdrive alt, underdrive water pump. alt and water pump were double underdriven. On top of that I had my e-fan on a temp probe. no on=off, no ign on switch. temp turned it on or off. double undrive alt, double underdive water pump AND the fan stayed on for 15 minutes after I turned my truck off. That pretty much satisfied any concerns i had

..just saved another $35 lol

what kind of gains have you seen with the UDP? is it worth the $285? some threads i have read say it is definately worth it and some say not worth it......what is your experience Wayne?

Did u see the pic of the white truck that said he didnt even have to powerbrake to spin the tires like was showed in the pic. Damn I would say thats good enough reason to get 1 for me and whoo hoo 1 and 1/2 more payments and truck is paid for. So about 2 months and I will have the extra cash to get me 1. When u gonna get u 1 lifted97 ?

i got 8hp on the dyno. i reset the computer so I think I lost some of the parameters from the stock run. I'm not sure.

asp got 16 hp and 12 torque. I don't doubt that run. i know these guys and they don't fluff things up. it is what it is in their minds. they make the run and move on.

bama said 4hp on a thread I read. It seemed odd, but the man owns his own dyno.

a lot of guys said it was the best hp mod so far.

i recently took mine off. i felt the difference. i go back to this- the pulley won't change any sensations. An intake or exhaust is gonna change the sound and give an impression based on it. The pulley is gonna add hp on a dyno and on the street. you won't hear it. this is the biggest thing to overcome in the perception of hp. 8 hp is in the range of 2/10's off you 1/4 mile time.

another thing to add is the hp is across the entire rpm band, from launch to finish line. Compare that to 10hp in a 1000 rpm range that you make get from an intake or exhaust. the pulley will net a bigger gain overall.

owe- they did LOWER the price in feb so I have them down to $250. I anticipate holding that price for the year if there are no surprises.

now...

thanks Wayne......i am going to your site to order 1 now :006: ........any HP increase when you have large tires and are low geared helps :crazy: